Reciprocating fluid motor



Nov. Il, 1966 W, G. MGKENZIE REGIPROCATING FLUID MOTOR Filed April 9, 1964 United States Patent O 3,282,167 RECWROCA'H G FLUKE MOTOR William G. McKenzie, Racine, Wis., assigner to Walker Manufacturing Company, Racine, Wis., a corporation of Delaware Filed Apr. 9, 1964, Ser. No. 358,493 12 Claims. (Cl. 91-306) This invention relates generally to iiuid pumping means and, more particularly, to a combination pneumatic-hydraulic power device which uses compressed air at a relatively low pressure to pump hydraulic uid at a relatively high pressure.

The power device of the present invention is particularly directed towards use in elevating relatively heavy loads on hydraulic service jacks of the type used in automotive vehicle repair shops and which include a hydraulic pressure-operated load lifting lever that is adapted to be elevated upon oscillation of a manipulating or pumping handle. The power device is adapted to be mounted on the jack handle or frame and use pressurized air from a common compressed air source to pump hydraulic fluid from the jacks fluid reservoir to its load-lifting ram assembly, thereby effecting elevation of the jacks lifting lever without requiring oscillation of the manipulating handle.

It is an object of the present invention to provide a pneumatic-hydraulic power device of the above character that is of an extremely compact construction.

It is another object of the present invention to provide a pneumatic-hydraulic pumping device of the above character which operates entirely automatically once pressurized air is communicated thereto.

It is still another object of the present invention to provide a power device of the above character that may be easily assembled and economically manufactured.

Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawing, wherein:

The figure is a longitudinal cross-sectional view of a preferred embodiment of the combined pneumatic-hydraulic power device of the present invention.

Referring now to the drawing, a combination pneumatic-hydraulic power device 1li', in accordance with a preferred embodiment of the present invention, is shown as including a hollow cylindrical pump housing 12 to which pressurized air is selectively transmitted from a pilot valve assembly 14 that is mounted on one (upper) side of the housing 12. The housing 12 comprises a cylindrical shell 16 which defines a pumping chamber 18 and which is closed on the opposite ends by a pair of substantially identical, combination header-displacement cylinder members 2@ and 22. The members 28 and 22 are respectively formed with axially outwardly extending pumping sections 24 and 26 and with radially outwardly extending header sections 28 and 38, respectively. A pair of axially aligned annular recesses 32 and 34 are respectively formed on the inner sides of the header sections 28 and 30 within which the opposite ends of the shell 16 are disposed. The header sections 28 and 30 are also formed with radially inwardly extending recesses 36 and 38 circumjacent the recesses 32 and 34, respectively, Within which sealing means in the form of O-rings 4t) and 42 are nested. A plurality of bolts, one of which is illustrated herein with suitable nuts 44, 46, and is designated by the numeral 48, are arranged circumferentially around the exterior of the shell 16 and extend axially through suitable aligned apertures in the outer peripheries of the header sections 28 and 30 to rigidly secure the members 20 and 22 to the opposite ends of the shell 16.

3,282,167 Patented Nov. l, 1966 The pumping sections 24 and 26 of the members 2t) and 22 are respectively formed with coaxial bores 50 and 52 which are communicable with the opposite sides of the displacement chamber 18. Slidably disposed within the bores 50 and 52 are elongated cylindrical hydraulic pistons 54 and 56, respectively. The inner ends of the pistons 54 and 56 are threaded into the opposite sides of a central sleeve section 58 of a double-acting pneumatic piston 6i) which is reciprocable within the chamber 18. The piston 60 lies in a radial plane perpendicular to the longitudinal axis of the housing 12 and is provided with a radially inwardly extending recess 62 around the periphery thereof, within which is disposed sealing. means in the form of an O-ring 64 that serves to p'rovide a slidable but air-tight seal between the shell 18 and the piston 60. The piston 60 divides the pumping chamber 18 into two adjacent chambers 18a and 18b, the first of which is adjacent the member 20 (on the right side of the piston 68), and the second of which is adjacent the member 22 (on the left side of the piston 60). To prevent hydraulic leakage from the interior of the bores 5t) and 52 into the chambers 18a and 18h, a plurality of packing rings, generally designated 66, are disposed circumjacent the pistons 54 and 56 and are operatively maintained within a pair of annular recesses 68 and 70 that are formed in the inner sides of the header sections 28 and 30 by gland nuts 72 and 74.

A pair of identical valve bores 76 and 78 are formed in the outer ends of the pumping sections 24 and 26 of the members 20 and 22 and are communicable through fluid passages 80 and 82 with the outer ends of the bores 50 and 52, respectively. Hydraulic fittings 84 and 86 are threaded within and communicate a pair of hydraulic conduits 88 and 90 with the valve bores 76 and 78, respectively. A pair of ball-type check valves 92 and 94 are resiliently seated within the bores 76 and 78 by suitable valve springs 96 and 98 and are adapted to control the flow of hydraulic pumping uid between the bores '76, 78 and the conduits 80, 82, respectively, as will be described.

A pair of check valve fittings 100 and 102 are threaded within appropriate radially outwardly extending bores formed in the outer ends of the pumping sections 24 and 26, respectively, which fittings are formed with valve bores 184 and 106 that communicate a second pair of hydraulic conduits 108 and 110 with a pair of radially inwardly extending bores 112 and 114 that are formed in the pumping sections 24 and 26. It will be seen that the bores 112 and 114 are communicable with the bores 80 and 82, respectively, adjacent the outer end of the bores 50 and 52, respectively. A pair of ball-type check valves 116 and 118 are resiliently seated within the fittings 180 and 102 by springs 120 and 122, respectively, and are adapted to control the ow of hydraulic pumping iiuid between the bores 112, 114 and the conduits 108, 118, respectively.

Referring now to the pilot valve assembly 14, there is provided a pilot valve housing, generally designated 124, that includes a hollow cylindrical shell 126 which defines a metering chamber 128. Extending axially outward from one (right) end of the shell 126 is an elongated cylindrical valve housing 130 that is formed with an outwardly extending flange section 132 which is attached to the end of the shell 126 by screws 134 and 136. Another valve housing 138, which is similar in construction to the housing 130, extends axially outward from the opposite (left) end of the shell 126 and is formed with an annular flange section which is attached to the end of the shell 126 with screws 142 and 144. Flat annular gaskets 146 and 148 are respectively interposed between the flange sections 132 and 140, and the opposite ends of the shell 126 to assure an air-tight seal therebetween. The valve housings 130 and 138 are respectively formed with axially extending valve bores 150 and 152 which communicate with the interior of the metering chamber 128 at the opposite ends of the shell 126. The valve bores 150 and 152 respectively define annular valve seats 154 and 156 against which ball-type check valves 158 and 160 are resiliently seated by valve springs 162 and 164, respectively. A pair of fittings 166 and 168 are respectively threaded within the outer ends of the bores 150 and 152 and respectively communicate the bores 150 and 152 with an air conduit 170 and a cross fitting 172, the latter of which is formed with intersecting air passages 174 and 176. As illustrated, the outer ends of the valve springs 162 and 164 bear against the inner ends of the fittings 166 and 168 to resiliently seat the valves 158 and 160, respectively.

A fiat annular piston 178, around which is disposed an O-ring sealing member 180, is reciprocable within the metering chamber 128. Formed on the opposite sides of the piston 178 is a pair of outwardly extending valve stems 182 and 184 which extend coaxially of and are slidable within the valve bores 150 and 152, respectively. The metering chamber 128 is formed with an annular shoulder 186 against which the piston 178 is resiliently urged by a coil spring 188 that extends within the chamber 128 circumjacent the valve stem 184. The outer (left) end of the spring 188 bears against a gland nut 190 which is threaded within the (left) end of the shell 126. A radially outwardly extending shoulder or stop 192 is formed on the valve stem 184 and is adapted to engage the inner end of the gland nut 190 to limit the reciprocal movement of the piston 178 within the chamber 128.

It will be seen that as the piston 17 8 reciprocates Within the metering chamber 128, the valve stems 182 and 184 will respectively reciprocate within the valve bores 150 and 152. The lengths of the valve stems 182 and 184 are designed such that when the piston 178 moves to the left, the valve stem 184 will unseat the ball valve 160, and conversely, when the piston 178 is in the position illustrated in the figure (at the far right hand end of its stroke), the valve stem 182 will unseat the ball valve 158. Thus, as the piston 178 reciprocates within the chamber 128, the ball valves 158 and 160 will be alternately unseated by the valve stems 182 and 184, and reseated by the springs 162 and 164.

A pair of fittings 194 and 196 are mounted within suitable apertures in the lower sides of the housings 130 and 138, respectively, and communicate a pair of air conduits 198 and 200 with the interior of the valve lbores 150 and 152, respectively. The opposite ends of the conduits 198 and 200 are communicable through a pair of fittings 202 and 204, and a pair of annular sleeves 206 and 208 which are disposed in the top and at the opposite ends of the shell 16, with the interior of the chambers 18a and 18b, respectively. It will thus be seen that the valve bores 150 and 152 are always communicable with the opposite sides of the piston 60 during its reciprocation within the housing 12.

A pair of exhaust vents 210 and 212 are formed in the pilot valve assembly housings 130 and 138, respectively, and are adapted to be communicable with the chambers 18a and 18b through the valve bores 150, 152 and the conduits 198, 200. Around the medial sections of the valve stems 182 and 184 are provided O-ring sealing means 214 and 216, respectively, which are adapted to reciprocate with the valve stems 182 and 184 and provide an air-tight seal between the interior of the chamber 128 and the valve bores 150 and 152, respectively. It will be seen that when the piston 178 is at the far right hand end of its stroke, as illustrated in the figure, the valve stem 184 is substantially retracted from the valve bore 152 and, accordingly, the O-ring 216 is disengaged from the inner periphery of the bore 152 and the exhaust vent 212 is in communication through the valve bore 152 and the conduit 200 with the interior of the chamber 18b. With the piston 178 in this position, the O-ring 214 is disposed in the valve bore 150 in a position such that it blocks cornmunication between the exhaust vent 210 and the interior of the chamber 18a. Conversely, when the piston 178 is 75 at the far and left hand end of its stroke, the O-ring 216, together with the valve stem 184 is disposed within the valve bore 152, thereby blocking communication between the exhaust vent 212 and the interior of the chamber 18b and the O-ring 214 is retracted from the bore and thus the exhaust vent 210 is in communication with the chamber 18a.

Referring again to the pump housing 12, it will be seen that the header sections 28 and 30 of the members 20 and 22 are respectively formed with enlarged valve sections 218 and 220. A pair of substantially axially aligned bores 222 and 224 are formed in the sections 218 and 220, which bores lie along a line substantially parallel to the longitudinal axis of the aforediscussed bores 50 and 52. Slidably disposed within the -bores 222 and 224 are a pair of cylindrical probes 226 and 228, respectively. Piston engaging head sections 230 and 232 are respectively formed on the probes 226 and 228 and extend into the interior of the chambers 18a and 18b from the inner sides of the header sections 28 and 30, respectively. A pair of leaf springs 234 and 236, which are respectively attached to the inner sides of the header sections 28 and 30 by suitable screws 238 and 240, extend through the head sections 230 and 232 of the probes 226 and 228 and resiliently maintain the probes 226 and 228 in a position where their head sections 230 and 232 extend into the chambers 18a and 18b, respectively. O-rings 241 and 242 are mounted on the probes 226 and 228, respectively, and provide slidable but air-tight seals between the probes 226, 228 and the bores 222, 224. The bores 222 and 224 are respectively formed with enlarged outer sections 243 and 244 within which are respectively disposed O-ring valve seats 246 and 248. A pair of ball-type check valves 250 and 252 are resiliently biased against the seats 246 and 248 by valve springs 254 and 256, respectively. The outer ends of the springs 254 and 256 respectively bear against fittings 258 and 260 which are threaded in the outer ends of the sections 243 and 244, and the latter of which communicates the section 244 with the passage 174 of the cross fitting 172 through a conduit 262 and a fitting 264.

The probes 226 and 228 are arranged within their respective valve bores 222 and 224 such that when the piston 60 -is at the far right hand end of its stroke, as illustrated by the solid lines in the figure, the probe 226 will be engaged by the piston and thereby be biased inwardly to unseat the ball valve 250. When the piston 60 is disengaged from the probe 228, the leaf spring 236 maintains this probe in the position illustrated, and the valve spring 256 resiliently seats the ball valve 252. In a similar manner, when the piston 60 is at the far left hand end of its stroke, as indicated by the phantom lines in the figure, the probe 228 is biased outwardly (to the left), thereby unseating the ball valve 252, during which time the probe 226 is also biased inwardly (to the left) by the spring 234, thereby permitting the spring 254 to seat the ball valve 250.

The valve sections 218 and 220 of the members 20 and 22 are further formed with upwardly extending passages 266 and 268, respectively, which are communicable with the bore section 243 and bore 224, respectively. Within the outer ends of the passages 266 and 268 are threaded fittings 270 and 273, which respectively communicate a pair of air conduits 272 and 274 with the passages 266 and 268. The opposite ends of the conduits 272 and 274 are communicable with `the opposite sides of a T-fitting 276 which is threaded within a passage 278 formed in the top of the shell 126 and communicating with the interior of the metering chamber 128. An air vent 280 is also formed in the section 218 which communicates the bore 222 with the exterior of the housing 12.

In operation, the power device 10 is preferably mounted on the jack frame or manipulating handle by a pair of mounting brackets 288 and 290 which are respectively secured to the members 20 and 22 by bolts 292 and 294. The conduits 88 and 90 are communicated with the jacks ram cylinder and the conduits 188 and 110 are communicated with the jacks fluid reservoir. Pressurized air is communicated to the device through a suitable air conduit 296 and may be controlled by ya manually operated air valve 298. The Valve 298 may be directly connected through a fitting 380 to the cross fitting 172 or alternatively, may be remotely communicated with the fitting 172 through a suitable conduit (not shown).

Upon appropriate actuation of the valve 298, pressurized air is communicated into the cross fitting 172 where it is allowed to go in three different directions. Assuming the pist-ons 6@ and 178 are in their respective positions illustrated in the figure, the air may flow through the passage 176 and pass into the valve bore 152 where its ow is s-topped. by the ball valve 160. Alternatively, air may also flow downward through the passage 174 and the conduit 262 into the bore section 244 where its fiow is stopped by the ball valve 252. The air in the fitting 1'72 may, however, flow through the conduit 170 and into the valve bore 158, past the ball valve 158 and then downward through the passage 198 into the chamber 18a. The air entering the chamber 18a through the conduit 198 forces the air piston 60 to the left until it engages the head section 232 of the probe 228, thereby unseatinig the ball valve 252. As the ball valve 252 thus becomes unseated, pressurized air is communicated through the conduit 262 from the T-fitti-ng 172 and into the passage 268 and. the conduit 274. The pressurized air within the conduit 274 flows into the T-fitting 276 and downward through the passage 278 in the sheel 124 into the metering chamber 128. It will be noted that at the time the piston 68 moves to the left, the probe 226 also moves to the left through the action of the leaf spring 234, thereby allowing the ball valve 258 to seat against the O-ring 246 to block communication between the valve bore 222 and the bore section 243. With the ball valve 50 thus seated, it will be seen that the pressurized air flowing from the cross fitting 172, around the ball valve 252 and u-pward int-o the conduit 174, will flow downward from the T-fitting 276 and into the cavity 128, thereby moving the piston 178 and the valve stems 182 and 184 to the left. As the valve stern 184 moves to the left within the valve bore 152, it engages and unseats the ball valve 160 while at the same time, the ball valve 158 is seated within the bore 158 by the spring 162. lt will be noted that as the piston 178 moves t-o the left, the Oring seal 214 is retracted. from the bore thereby opening a passage from the chamber 18a, through the conduit 198 and bore 150, to the exhaust vent 210.

It will be seen that once the piston 178 has moved to the left, thereby unseating the ball valve 160 and concurrently allowiug the ball valve 158 to be seated within the bore 151), the ow of pressurized air from the cross fitting 172 will pass through the fitting 168 and into the cylinder 138, from where it will flow downward through the conduit 200 into the interior of the chamber ber 18a, it engages the probe 226 therelby unseatng the ball piston 68 leaves the left hand side of the housing 12 (that position indicated by the phantom lines), the probe 228 will be biased inwardly (to the right) by the spring 236, thereby allowing the ball valve 252 to sea-t within the bore section 244. During the time the air piston 60 moves from left to right, it will be seen that the air pressure within the conduit 272 and the chamber 128 is trapped so that the piston 178 cannot move. When the air piston 68 reaches the far right side of the chamber 18a, it engages the probe 226 thereby unseating the ball valve 250 and permitting air trapped within the conduit 272 and the chamber 128 to exhaust through the bore section 243 and air vent 288. As the air exhausts from the chamber 128, the spring 188 resiliently biases the piston 178 to the right, thereby engaging and unseating the ball valve 158 with the Valve stem 182 and biasing the O-ring 214 into the bore 150 to block communication between the exhaust vent 218 and the interior of the chamber 18a. Also, movement of the piston 178 to the right withdraws the O-rinig 216 from the bore 152, thereby allowing pressurized air to flow from the chamber 181) through the condui-t 280 and exhaust vent 212. It will be apparent, of course, that as the valve stem 182 unseats the ball valve 158, the entire pumping device 18 will begin its next successive cycle, identical to that hereinbefore described.

As the air piston 60 reciprocates within the pump housing 12, the hydraulic pistons 54 and 56, which are attached to the opposite sides of the air piston 60, reciprocate within the cylinders 24 and 26. As the piston 56 moves to the right within the bore 52, hydraulic fluid communicated to the fitting 102 from the jacks fluid reservoir through the conduit 118 will unseat the ball valve 118 and flow into the bore 52. At such time as the piston 56 moves outward wi-thin the bore 52, the hydraulic fluid within the bore 52 will seat the valve 118 and unseat the ball valve 94, and thus be pumped through the conduit to the load-lifting ram cylinder of the jack. In a similar manner, as the piston 54 reciprocates within the bore 50, hydraulic fluid is pumped into the cylinder 24 through the conduit 108 and past the ball valve 116, and is pumped. from the cylinder 24 thr-ough the conduit 88 past the ball valve 92. It will thus be seen that as the air cylinder 60 reciprocates within the pump housing 12, the piston 54 will draw hydraulic fluid into the bore 5t) while the piston 56 simultaneously discharges fiuid from the bore 52, and conversely, as the piston 56 draws fluid into the bore 52, the piston 54 simultaneously discharges fluid from the bore 50. It will thus be apparent that a continuous flow of hydraulic fiuid will be pumped to the jack during the entire time pressurized air is communicated to the power device 10.

It wil be evident from the aforegoing construction that the power device 18 of the present invention provides an extremely compact unit which is adapted to be easily installed or mounted on a hydraulic service jack and operate to efficiently pump hydraulic fluid to the jacks ram cylinder to effect elevation of the jacks lifting lever, without requiring any effort on the part of the jack operator other than actuating the valve 298. Moreover, by virtue of the relatively simple construction of the power device 18, it will be apparent that the unit will be -both dependable in operation and economical to commercially produce.

While it will be apparent that the preferred embodiment herein illustrated is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1- In a combination pneumatic-hydraulic pumping device,

a pump housing comprising an annular shell and header means closing the opposite ends of said shell,

said header means defining hydraulic pumping chambers communicable with the interior of said shell,

-a pneumatically actuated piston reciprocable within said Shell,

hydraulic pumping means attached to the opposite sides of said piston and reciprocable within said hydraulic pumping chambers upon reciprocation of said piston in said shell,

valve means for selectively metering predetermined quantities of pressurized air into said shell on the opposite sides of said piston to effect the movement of said piston and said hydraulic pumping means,

said valve means comprising a valve housing and a pressure responsive piston reciprocable within said housing,

conduit means communicating said valve housing with said pump housing,

check valve means in said valve housing and being selectively engageable by said piston means in said valve housing to communicate pressurized air from said valve housing into said conduit means, and

means including probe means slidably mounted in said pump housing and engageable by said pneumatically actuated piston to effect the actuation of said valve means.

2. In a uid pumping device,

a pump housing,

a pumping chamber in said housing,

a piston reciprocable in said housing,

at least a portion of said piston being reciprocable in said pumping chamber,

uid inlet land outlet means communicable with said pumping chamber,

valve means for selectively metering predetermined quantities of an actuating fluid into said pump housing to effect the movement of said piston,

said valve means including a valve housing which comprises a central section and check valve sections on the opposite sides of said central section,

said valve means further including a piston reciprocable within said central section and having valve stems reciprocable within said check valve sections upon reciprocation of said last mentioned piston in said central section,

check valve means in each of said check valve sections of said valve housing, and

conduit means communicating said valve housing with said pump housing,

said piston in said valve housing being movable therein in response to movement of said piston in said pump housing thereby effecting movement of said valve stems to unseat said check valve means and communicate pressurized air to said pump housing.

3. In a fluid pumping device,

a pump housing comprising a central section and a pair of pumping chambers,

a piston having an actuating section and a pair of pumping sections respectively reciprocable within said central section and said pumping sections,

fluid inlet and outlet means communicating pumping uid to and from said pumping chambers,

valve means for selectively metering predetermined quantities of pressurized air into said central section of said pump housing on the opposite sides of said actuating section of said pist-on to effect the movement of said piston,

said valve means comprising a Valve housing and -a pressure responsive piston reciprocable within said valve housing,

conduit means communicating said valve housing with said pump housing,

check valve means in said valve housing and being selectively engageable by said piston means in said valve housing to communicate pressurized air from said valve housing into said conduit means, and

means including probe means slidably mounted in said pump housing and engageable by said piston in said pump housing to effect the acuation of said valve means.

4. In a combination pneumatic-hydraulic pumping device,

a pump housing comprising a pneumatic pumping chamber and a pair of hydraulic pumping chambers,

a piston reciprocable within said pneumatic pumping chamber,

hydraulic pumping means reciprocable within said hydraulic pumping chambers,

hydraulic uid inlet and outlet means communicating hydraulic iluid to and from said hydraulic pumping chambers,

valve means for selectively metering predetermined quantites of pressurized air into said pneumatic pumping chamber on the opposite sides of said piston to effect the movement of said piston and said hydraulic pumping means,

said valve means comprising a valve housing and a pressure responsive piston reciprocable within said valve housing,

conduit means communicating said valve housing with said pump housing,

check valve means in said valve housing and being selectively engageable by said piston means in said valve housing to communicate pressurized air from said valve housing into said conduit means, and

means including probe means slidably mounted in said pump housing and engageable by said piston in said pump housing to effect the actuation of said valve means.

5. In a combination pneumatic-hydraulic power device,

a pump housing comprising a pneumatic pumping chamber and a pair of hydraulic pumping chambers,

a piston reciprocable within said pneumatic pumping chamber,

hydraulic pumping means reciprocable within said hydraulic pumping chambers,

v-alve means for selectively metering predetermined quantities of pressurized air into said pneumatic pumping chamber on the opposite sides of said piston to effect the movement of said piston and said hydraulic pumping means,

said valve means comprising a valve housing and a pressure responsive piston reciprocable within said valve housing,

conduit means communicating said valve housing with said pump housing,

check valve means in said valve housing and being selectively engageable by said piston means in said valve housing to communicate pressurized air from said valve housing into said conduit means, and

means in said pneumatic pumping chamber responsive to the movement of said rst mentioned piston to communicate pressurized air to said valve housing thereby effecting movement of said pressure responsive piston.

6. In a combination pneumatic-hydraulic power device,

a pump housing comprising a pneumatic pumping chamber and a pair of hydraulic pumping chambers,

a piston reciprocable within said pneumatic pumping chamber,

hydraulic pumping means reciprocable within said hydraulic pumping chambers,

valve means for communicating preselected quantities of an actuating fluid into said pump housing to effect the movement of said piston,

said valve means including a valve housing which comprises a central section and check valve sections on the opposite sides of said central section,

said valve means further including a piston reciprocable within said central section and having valve stems reciprocable within said check valve sections upon reciprocation of said piston in said central section,

check valve means in each of said check valve sections of said valve housing, and

conduit means communicating said valve housing with said pump housing, and

means including probe means slidably mounted in said pump housing and engagea'ble -by said pneumatically -actuated piston to effect the actuation of said valve means,

said piston in said valve housing being movable therein in response to movement of said piston in said pump housing to effect movement of said valve stems to unseat said check valve means and communicate pressurized air to said pump housing.

7. In a combination pneumatic-hydraulic power dea pump housing `corn-prising an annular shell and header means closing the opposite ends of said shell,

said header means deiining hydraulic pumping cham- Ibers communicable with the interior of said shell,

a pneumatically actuated piston reciproca-ble within said shell,

hydraulic pumping means Iattached to the opposite sides of said piston and reciprocable within said hydraulic pumping cham-bers upon reciprocation of said piston in said shell,

valve means for communicating preselected quantities of pressurized air into said pump housing to effect the movement of said piston,

said valve means including a valve housing which comprises a central section and check valve sections on the opposite sides of said central section,

said valve means further including a piston reciprocable within said central section and having valve stems reciprocable within said check valve sections upon reciprocation of said piston in said central section,

check valve means in each of said check valve sections of said valve housing,

conduit means communicating said valve housing with said pump housing, and

means including probe means slidably mounted in said pump housing and engageable by said pneumatically actuated piston to elect the actuation of said valve means,

said piston in said valve housing being movable therein in response to movement of said piston in said pump housing to effect movement of said valve stems to unseat said check valve means and communicate pressurized air to said pump housing.

8. In a pneumatically powered pumping device,

a `pump housing comprising a hollow cylindrical shell,

the opposite ends of said shell being closed by header members each of which denes a hydraulic pumping chamber,

a pneumatically actuated piston reciprocable within said shell,

a hydraulic piston attached to each side of said pneumatically actuated piston and being reciprocable Within said hydraulic pumping chambers,

valve means for selectively communicating pressurized air into said pump housing to effect the movement of said pneumatically actuated piston,

said valve means including a valve housing which com- `prises a central section and check valve sections on the opposite sides of said central section,

said valve means further including a piston recipro- -cable within said central section and having valve `stems reciprocable within said check valve sections upon reciprocation of said piston in said central section,

check valve means in each of said check valve sections of said valve housing,

conduit means communicating said valve housing with said pump housing,

said piston in said valve housing being movable therein in response to movement of said piston in said Ipump housing to effect movement of said valve stems to unseat said check valve means and communicate pressurized air to said pump housing,

lprobe means slidably mounted in said header members and being alternately -engageable by said pneumatically actuated piston as it reciprocates within said shell, and

conduit means communicating said probe means with said valve housing and communicating pressurized air from said shell to said valve housing upon engagement of said probe means by said pneumatically actuated piston.

9. In a pneumatically air-power pum-ping device,

a pump housing comprising .a hollow cylindrical shell,

the opposite ends of said shell being closed by header members each of which denes a hydraulic pumping chamber,

a pneumatically actuated pist-on reciprocable within said shell,

a 'hydraulic piston attached to each side of said pneumatically actuated piston and Ibeing reciprocable within said hydraulic pumping chambers,

valve means for communicating preselected quantities `of an actuating fluid into said pump housing to effect the ymovement of said pneumatically actuated piston,

sai-d valve means including a valve housing which cornprises a central section and check valve sections on the opposite sides of said central section,

said valve means further including a piston reciproca-ble within said central section and having valve stems reciprooable within said check valve sections upon reciprocation of said piston in said central section,

check valve means in each of said check valve sections of said valve housing,

conduit means communicating said valve housing with said pump housing,

said piston in said valve housing `being movable therein in response to movement `of said piston in said pump housing to eiect movement of said valve stems to u-nseat said check valve means and communicate pressurized air to said pump housing,

probe means slidably mounted in said header members land being alternately engageable by said pneumatically actuated piston as it reciprocates within said shell,

conduit means communicating said probe means with said valve hou-sing and communicating pressurized air from said shell to said valve housing upon engagement of said probe means by said pneumatically actuated piston,

check valve means in said header members adjacent each of said probe means and selectively blocking communication between said last referred to conduit means and lsaid valve housing,

said last referred to check valve means 'being unseated upon engagement of said pneumatically yactuated piston with the adjacent of said probe means whereby pressurized air is communicated from said shell to said valve housing through said 'last mentioned oonduit means.

l0. In la combination pneumatic-hydraulic pumping device,

a pump housing comprising an annular shell and header means closing the opposite ends of said shell,

said header means defining hydraulic pumping chambers communicating with the interior of said shell,

a pneumatically actuated piston reciprocable within said shell,

hydraulic pumping means attached to the opposite sides of said piston and reciprocable within said hydraulic pumping chambers upon reciprocation of said piston in said shell,

a pilot vla'lve assembly comp-rising a valve housing having a central section and check valve sections on the opposite sides of said central section,

a pilot 'valve piston reciprceable within said central section of said valve housing and having valve stems attached to the opposite sides thereof that are reciprocable within said check valve sections,

conduit means communicating said check valve sections of said valve housing with said pump housing on the opposite sides of said pneumatically .actuated piston, and

check valve means in said check valve sections blocking communication between said central :section and said conduit means,

said check valve means being engageable by said valve stems to communicate said central section of said valve housing with said shell through said conduit means.

11. The device as set forth in claim which includes a pressurized air inlet line communicable with each of said `check valve sections of said vialve housing and wherein said check valve Imeans upon being engaged by said valve stems on said pilot valve piston communicate said air pressurized air inlet line with said shell through said conduit means.

12. In 1a pneumatically operated device for powering a hydraulic service jack or the like,

a pump housing comprising a hollow annular shell,

the opposite ends of said shell `being closed by header members each of which denes a hydraulic pumping chamber,

a pneumatically actuated piston recirpocable within said shell,

a hydraulic piston attached to each side of said pneumatically actuated piston and being reciproca-ble within said hydraulic pumping chambers upon the reciprocation of said pneumatically actuated piston in said shell,

hydraulic inlet and outlet conduits communicating hydraulic iluid to and from said hydraulic pumping chambers,

check valves selectively blocking communication between said inlet yand outlet conduits and said hydraulic 4pumping chambers,

a pilot valve assembly comprising a valve housing having a central section `and check valve sections on the opposite sides of said central section,

a pilot valve piston reciprocable within said central sec- 3 tion of said valve housing and having valve stems attached to the opposite sides thereof that are reciprocable within said check valve sections,

conduit means Icommunicating said check valve sections of said valve housing with said pump housing on the opposite sides of said pneumatica'lly actuated piston,

check valves in :said check valve sections blocking communication between said central section of said valve housing yand said last mentioned conduit means,

said last me-ntioned check valves being engageable by said valve stems to communicate said central section with said last mentioned oon-duit means,

a pair of probes slidvably and resiliently 4mounted in said header members and 'being alternately engageable by said pneumatically actuated piston as it reciprocates within `said shell,

conduit means communicating said probes with said valve housing and communicating pressurized air to said valve housing upon engagement of said probes by .said pneumatically actuated piston,

check valve means in said header members adjacent each of said probes selectively blocking communication between said last referred to conduit 'means and said valve housing,

said last referred to check valve means being adapted to be unseated upon engagement of said pneumatically actuated piston with the `adjacent of said probe means thereby communicating pressurized air to said valve housing through said last mentioned conduit means to eect the movement of said piston in said valve housing.

References Cited by the Examiner UNITED STATES PATENTS 627,399 6/1899 Donge's et al. 91-313 986,592 3/1911 Rankin 91-306 3,070,023 12/1962 Glasgow 91-313 3,162,093 12/1964 Zoller 91-306 MARTIN P. SCHWADRON, Primary Examiner.

SAMUEL LEVINE, Examiner.

P. E. MASLOUSKY, Assistant Examiner. 

1. IN A COMBINATION PNEUMATIC-HYDRAULIC PUMPING DEVICE, A PUMP HOUSING COMPRISING AN ANNULAR SHELL AND HEADER MEANS CLOSING THE OPPOSITE ENDS OF SAID SHELL, SAID HEADER MEANS DEFINING HYDRAULIC PUMPING CHAMBERS COMMUNICABLE WITH THE INTERIOR OF SAID SHELL, A PNEUMATICALLY ACTUATED PISTON RECIPROCABLE WITHIN SAID SHELL, HYDRAULIC PUMPING MEANS ATTACHED TO THE OPPOSITE SIDES OF SAID PISTON AND RECIPROCABLE WITHIN SAID HYDRAULIC PUMPING CHAMBERS UPON RECIPROCATION OF SAID PISTON IN SAID SHELL, VALVE MEANS FOR SELECTIVELY METERING PREDETERMINED QUANTITIES OF PRESSURIZED AIR INTO SAID SHELL ON THE OPPOSITE SIDES OF SAID PISTON TO EFFECT THE MOVEMENT OF SAID PISTON AND SAID HYDRAULIC PUMPING MEANS, SAID VALVE MEANS COMPRISING A VALVE HOUSING AND A PRESSURE RESPONSIVE PISTON RECIPROCABLE WITHIN SAID HOUSING, CONDUIT MEANS COMMUNICATING SAID VALVE HOUSING WITH SAID PUMP HOUSING, CHECK VALVE MEANS IN SAID VALVE HOUSING AND BEING SELECTIVELY ENGAGEABLE BY SAID PISTON MEANS IN SAID VALVE HOUSING TO COMMUNICATE PRESSURIZED AIR FROM SAID VALVE HOUSING INTO SAID CONDUIT MEANS, AND MEANS INCLUDING PROBE MEANS SLIDABLY MOUNTED IN SAID PUMP HOUSING AND ENGAGEABLE BY SAID PNEUMATICALLY ACTUATED PISTON TO EFFECT THE ACTUATION OF SAID VALVE MEANS. 